今天就跟大家聊聊有關.NET Core如何使用Kafka，可能很多人都不太了解，為了讓大家更加了解，小編給大家總結了以下內容，希望大家根據這篇文章可以有所收獲。
安裝
CentOS安裝 kafka
下載并解壓
# 下載，并解壓 $ wget https://archive.apache.org/dist/kafka/2.1.1/kafka_2.12-2.1.1.tgz $ tar -zxvf kafka_2.12-2.1.1.tgz $ mv kafka_2.12-2.1.1.tgz /data/kafka # 下載 zookeeper，解壓 $ wget https://mirror.bit.edu.cn/apache/zookeeper/zookeeper-3.5.8/apache-zookeeper-3.5.8-bin.tar.gz $ tar -zxvf apache-zookeeper-3.5.8-bin.tar.gz $ mv apache-zookeeper-3.5.8-bin /data/zookeeper
啟動 ZooKeeper
# 復制配置模版 $ cd /data/kafka/conf $ cp zoo_sample.cfg zoo.cfg # 看看配置需不需要改 $ vim zoo.cfg # 命令 $ ./bin/zkServer.sh start # 啟動 $ ./bin/zkServer.sh status # 狀態 $ ./bin/zkServer.sh stop # 停止 $ ./bin/zkServer.sh restart # 重啟 # 使用客戶端測試 $ ./bin/zkCli.sh -server localhost:2181 $ quit
啟動 Kafka
# 備份配置 $ cd /data/kafka $ cp config/server.properties config/server.properties_copy # 修改配置 $ vim /data/kafka/config/server.properties # 集群配置下，每個 broker 的 id 是必須不同的 # broker.id=0 # 監聽地址設置（內網） # listeners=PLAINTEXT://ip:9092 # 對外提供服務的IP、端口 # advertised.listeners=PLAINTEXT://106.75.84.97:9092 # 修改每個topic的默認分區參數num.partitions，默認是1，具體合適的取值需要根據服務器配置進程確定，UCloud.ukafka = 3 # num.partitions=3 # zookeeper 配置 # zookeeper.connect=localhost:2181 # 通過配置啟動 kafka $ ./bin/kafka-server-start.sh config/server.properties& # 狀態查看 $ ps -ef|grep kafka $ jps
docker下安裝Kafka
docker pull wurstmeister/zookeeper docker run -d --name zookeeper -p 2181:2181 wurstmeister/zookeeper
docker pull wurstmeister/kafka docker run -d --name kafka --publish 9092:9092 --link zookeeper --env KAFKA_ZOOKEEPER_CONNECT=zookeeper:2181 --env KAFKA_ADVERTISED_HOST_NAME=192.168.1.111 --env KAFKA_ADVERTISED_PORT=9092 wurstmeister/kafka
介紹
kafka partition 和 consumer 數目關系
在 .NET Core 項目中安裝組件
Install-Package Confluent.Kafka
開源地址： https://github.com/confluentinc/confluent-kafka-dotnet
添加 IKafkaService 服務接口
public interface IKafkaService
{
/// <summary>
/// 發送消息至指定主題
/// </summary>
/// <typeparam name="TMessage"></typeparam>
/// <param name="topicName"></param>
/// <param name="message"></param>
/// <returns></returns>
Task PublishAsync<TMessage>(string topicName, TMessage message) where TMessage : class;
/// <summary>
/// 從指定主題訂閱消息
/// </summary>
/// <typeparam name="TMessage"></typeparam>
/// <param name="topics"></param>
/// <param name="messageFunc"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
Task SubscribeAsync<TMessage>(IEnumerable<string> topics, Action<TMessage> messageFunc, CancellationToken cancellationToken) where TMessage : class;
}實現 IKafkaService
public class KafkaService : IKafkaService
{
public async Task PublishAsync<TMessage>(string topicName, TMessage message) where TMessage : class
{
var config = new ProducerConfig
{
BootstrapServers = "127.0.0.1:9092"
};
using var producer = new ProducerBuilder<string, string>(config).Build();
await producer.ProduceAsync(topicName, new Message<string, string>
{
Key = Guid.NewGuid().ToString(),
Value = message.SerializeToJson()
});
}
public async Task SubscribeAsync<TMessage>(IEnumerable<string> topics, Action<TMessage> messageFunc, CancellationToken cancellationToken) where TMessage : class
{
var config = new ConsumerConfig
{
BootstrapServers = "127.0.0.1:9092",
GroupId = "crow-consumer",
EnableAutoCommit = false,
StatisticsIntervalMs = 5000,
SessionTimeoutMs = 6000,
AutoOffsetReset = AutoOffsetReset.Earliest,
EnablePartitionEof = true
};
//const int commitPeriod = 5;
using var consumer = new ConsumerBuilder<Ignore, string>(config)
.SetErrorHandler((_, e) =>
{
Console.WriteLine($"Error: {e.Reason}");
})
.SetStatisticsHandler((_, json) =>
{
Console.WriteLine($" - {DateTime.Now:yyyy-MM-dd HH:mm:ss} > 消息監聽中..");
})
.SetPartitionsAssignedHandler((c, partitions) =>
{
string partitionsStr = string.Join(", ", partitions);
Console.WriteLine($" - 分配的 kafka 分區: {partitionsStr}");
})
.SetPartitionsRevokedHandler((c, partitions) =>
{
string partitionsStr = string.Join(", ", partitions);
Console.WriteLine($" - 回收了 kafka 的分區: {partitionsStr}");
})
.Build();
consumer.Subscribe(topics);
try
{
while (true)
{
try
{
var consumeResult = consumer.Consume(cancellationToken);
Console.WriteLine($"Consumed message '{consumeResult.Message?.Value}' at: '{consumeResult?.TopicPartitionOffset}'.");
if (consumeResult.IsPartitionEOF)
{
Console.WriteLine($" - {DateTime.Now:yyyy-MM-dd HH:mm:ss} 已經到底了：{consumeResult.Topic}, partition {consumeResult.Partition}, offset {consumeResult.Offset}.");
continue;
}
TMessage messageResult = null;
try
{
messageResult = JsonConvert.DeserializeObject<TMessage>(consumeResult.Message.Value);
}
catch (Exception ex)
{
var errorMessage = $" - {DateTime.Now:yyyy-MM-dd HH:mm:ss}【Exception 消息反序列化失敗，Value：{consumeResult.Message.Value}】 ：{ex.StackTrace?.ToString()}";
Console.WriteLine(errorMessage);
messageResult = null;
}
if (messageResult != null/* && consumeResult.Offset % commitPeriod == 0*/)
{
messageFunc(messageResult);
try
{
consumer.Commit(consumeResult);
}
catch (KafkaException e)
{
Console.WriteLine(e.Message);
}
}
}
catch (ConsumeException e)
{
Console.WriteLine($"Consume error: {e.Error.Reason}");
}
}
}
catch (OperationCanceledException)
{
Console.WriteLine("Closing consumer.");
consumer.Close();
}
await Task.CompletedTask;
}
}注入 IKafkaService ，在需要使用的地方直接調用即可。
public class MessageService : IMessageService, ITransientDependency
{
private readonly IKafkaService _kafkaService;
public MessageService(IKafkaService kafkaService)
{
_kafkaService = kafkaService;
}
public async Task RequestTraceAdded(XxxEventData eventData)
{
await _kafkaService.PublishAsync(eventData.TopicName, eventData);
}
}以上相當于一個生產者，當我們消息隊列發出后，還需一個消費者進行消費，所以可以使用一個控制臺項目接收消息來處理業務。
var cts = new CancellationTokenSource();
Console.CancelKeyPress += (_, e) =>
{
e.Cancel = true;
cts.Cancel();
};
await kafkaService.SubscribeAsync<XxxEventData>(topics, async (eventData) =>
{
// Your logic
Console.WriteLine($" - {eventData.EventTime:yyyy-MM-dd HH:mm:ss} 【{eventData.TopicName}】- > 已處理");
}, cts.Token);在 IKafkaService 中已經寫了訂閱消息的接口，這里也是注入后直接使用即可。
生產者消費者示例
生產者
static async Task Main(string[] args)
{
if (args.Length != 2)
{
Console.WriteLine("Usage: .. brokerList topicName");
// 127.0.0.1:9092 helloTopic
return;
}
var brokerList = args.First();
var topicName = args.Last();
var config = new ProducerConfig { BootstrapServers = brokerList };
using var producer = new ProducerBuilder<string, string>(config).Build();
Console.WriteLine("\n-----------------------------------------------------------------------");
Console.WriteLine($"Producer {producer.Name} producing on topic {topicName}.");
Console.WriteLine("-----------------------------------------------------------------------");
Console.WriteLine("To create a kafka message with UTF-8 encoded key and value:");
Console.WriteLine("> key value<Enter>");
Console.WriteLine("To create a kafka message with a null key and UTF-8 encoded value:");
Console.WriteLine("> value<enter>");
Console.WriteLine("Ctrl-C to quit.\n");
var cancelled = false;
Console.CancelKeyPress += (_, e) =>
{
e.Cancel = true;
cancelled = true;
};
while (!cancelled)
{
Console.Write("> ");
var text = string.Empty;
try
{
text = Console.ReadLine();
}
catch (IOException)
{
break;
}
if (string.IsNullOrWhiteSpace(text))
{
break;
}
var key = string.Empty;
var val = text;
var index = text.IndexOf(" ");
if (index != -1)
{
key = text.Substring(0, index);
val = text.Substring(index + 1);
}
try
{
var deliveryResult = await producer.ProduceAsync(topicName, new Message<string, string>
{
Key = key,
Value = val
});
Console.WriteLine($"delivered to: {deliveryResult.TopicPartitionOffset}");
}
catch (ProduceException<string, string> e)
{
Console.WriteLine($"failed to deliver message: {e.Message} [{e.Error.Code}]");
}
}
}消費者
static void Main(string[] args)
{
if (args.Length != 2)
{
Console.WriteLine("Usage: .. brokerList topicName");
// 127.0.0.1:9092 helloTopic
return;
}
var brokerList = args.First();
var topicName = args.Last();
Console.WriteLine($"Started consumer, Ctrl-C to stop consuming");
var cts = new CancellationTokenSource();
Console.CancelKeyPress += (_, e) =>
{
e.Cancel = true;
cts.Cancel();
};
var config = new ConsumerConfig
{
BootstrapServers = brokerList,
GroupId = "consumer",
EnableAutoCommit = false,
StatisticsIntervalMs = 5000,
SessionTimeoutMs = 6000,
AutoOffsetReset = AutoOffsetReset.Earliest,
EnablePartitionEof = true
};
const int commitPeriod = 5;
using var consumer = new ConsumerBuilder<Ignore, string>(config)
.SetErrorHandler((_, e) =>
{
Console.WriteLine($"Error: {e.Reason}");
})
.SetStatisticsHandler((_, json) =>
{
Console.WriteLine($" - {DateTime.Now:yyyy-MM-dd HH:mm:ss} > monitoring..");
//Console.WriteLine($"Statistics: {json}");
})
.SetPartitionsAssignedHandler((c, partitions) =>
{
Console.WriteLine($"Assigned partitions: [{string.Join(", ", partitions)}]");
})
.SetPartitionsRevokedHandler((c, partitions) =>
{
Console.WriteLine($"Revoking assignment: [{string.Join(", ", partitions)}]");
})
.Build();
consumer.Subscribe(topicName);
try
{
while (true)
{
try
{
var consumeResult = consumer.Consume(cts.Token);
if (consumeResult.IsPartitionEOF)
{
Console.WriteLine($"Reached end of topic {consumeResult.Topic}, partition {consumeResult.Partition}, offset {consumeResult.Offset}.");
continue;
}
Console.WriteLine($"Received message at {consumeResult.TopicPartitionOffset}: {consumeResult.Message.Value}");
if (consumeResult.Offset % commitPeriod == 0)
{
try
{
consumer.Commit(consumeResult);
}
catch (KafkaException e)
{
Console.WriteLine($"Commit error: {e.Error.Reason}");
}
}
}
catch (ConsumeException e)
{
Console.WriteLine($"Consume error: {e.Error.Reason}");
}
}
}
catch (OperationCanceledException)
{
Console.WriteLine("Closing consumer.");
consumer.Close();
}
}
看完上述內容，你們對.NET Core如何使用Kafka有進一步的了解嗎？如果還想了解更多知識或者相關內容，請關注億速云行業資訊頻道，感謝大家的支持。
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